Field of the Disclosure
The present disclosure relates to a display device, and more particularly, to an irregular shape display (or non-tetragonal-shaped display) having a hole.
Description of the Background
In recent information society, the importance of display (or display devices) is more emphasized as a visual information transmission medium, but their requirements such as low power consumption, thin profile, light weight, high picture quality should be satisfied in order to take the principal position in the future.
Display devices can be divided into an emissive type display capable of spontaneously emitting light such as cathode ray tube (CRT), electro luminescence (EL), light emitting diode (LED), vacuum fluorescent display (VFD), field emission display (FED), plasma display panel (PDP), and the like, and a non-emissive type display incapable of spontaneously emitting light such as liquid crystal display (LCD) device.
The liquid crystal display is a device for implementing images using optical anisotropy of liquid crystal molecules, and in recent years, it has been mostly used as a device along with a PDP display because its visibility is more excellent than a CRT, and its average power consumption and heat dissipation is lower than that of the CRT with the same screen size.
Hereinafter, a typical liquid crystal display device will be described in detail.
In general, a liquid crystal display device may individually supply a data signal according to image information to pixels arranged in a matrix form and adjust the light transmittance of the pixels to display a desired image.
Accordingly, the liquid crystal display (LCD) may include a liquid crystal panel in which pixels are arranged in a matrix form, and a drive unit for driving pixels and a backlight unit for supplying light to the liquid crystal panel.
FIG. 1 is an exploded perspective view schematically illustrating the structure of a typical liquid crystal display device.
Furthermore, FIG. 2 is a view schematically illustrating a cross-section taken along line A-A′ in the typical liquid crystal display device illustrated in FIG. 1.
FIG. 3 is a view schematically illustrating a cross-section taken along line B-B′ in the typical liquid crystal display device illustrated in FIG. 1. More specifically, FIG. 3 schematically illustrates a lower cross-section of a liquid crystal display device at which an LED array is located.
Referring to FIGS. 1 through 3, the typical liquid crystal display device includes a liquid crystal panel 10 in which pixels are arranged in a matrix form to display an image, and a drive unit (not shown) for driving pixels, a backlight unit 40 provided on a rear surface of the liquid crystal panel 10 to emit light over the entire surface of the liquid crystal panel 10, and a lower cover 50 for accommodating and fixing the liquid crystal panel 10 and backlight unit 40.
The liquid crystal panel 10 includes a color filter substrate 5 bonded thereto to maintain a uniform cell gap to face each other, an array substrate 15, and a liquid crystal layer (not shown) formed in a cell gap between the color filter substrate 5 and array substrate 15.
Upper and lower polarizers 1, 11 are respectively adhered to an outer side of the liquid crystal panel 10, wherein the lower polarizer 11 polarizes light passed through the backlight unit 40, and the upper polarizer 1 polarizes light passed through the liquid crystal panel 10.
Describing the backlight unit 40 in detail, a light emitting diode (LED) assembly 30 for emitting light is provided at one side of a light guide plate 42, and a reflector 41 is provided on a rear surface of the light guide plate 42.
Further, the LED assembly 30 includes an LED array 31, an LED array printed circuit board (PCB) (not shown) for driving the LED array 31, and a housing 32.
Light emitted from the LED array 31 is entered to a lateral surface of the light guide plate 42 having a transparent material, and the reflector 41, and the reflector 41 disposed on a rear surface of the light guide plate 42 reflects light transmitted through the rear surface of the light guide plate 42 to the side of optical sheets on the upper surface of the light guide plate 42 to reduce the loss of light and enhance the uniformity.
The liquid crystal panel 10 consisting of the color filter substrate 5 and array substrate 15 is mounted on an upper portion of the backlight unit 40 having the foregoing configuration through a guide panel 45, and the lower cover 50 is coupled to a lower portion thereof to constitute a liquid crystal display device.
In other words, the liquid crystal panel 10 is mounted on mounting portions 45a, 45b of the guide panel 45 through an adhesive tape 46, and the lower cover 50 is coupled to a fastening portion 45′ on a lateral surface of the guide panel 45 through a hook 51 at an outer side thereof.
Here, a product with a circular shape out of the existing rectangular design may be referred to as an irregular shape display, and the different form has the meaning that the property, shape, type of things are different from the existing things. In other words, an irregular shape display refers to as a display having a shape of which is modified in various ways such as a circular or diamond shape out of the existing or traditional rectangular display.
Since the irregular shape display is fabricated in various shapes contrary to the existing rectangular display, and the fabrication process thereof is important. Furthermore, a very thin bezel that is capable of satisfying user's convenience as well as trendier and slimmer than the conventional products should be necessary.
Here, when the guide panel 45 formed of a mold is applied thereto, a molding thickness of at least 0.6-0.8 mm is required, and thus restrictive in applying a narrow bezel structure less than 1.5 mm.
Furthermore, the molding and dimensional design error is more restrictive in a structure to which the foregoing hook 51 is applied to an outer side of the lower cover 50 or the hook is applied to an inner side of the guide panel 45.
In other words, the fixing structure of a typical optical sheet requires a minimum of 1.0 mm for an amount of bite (overlapping width) (b, c shown in FIGS. 2 and 3, respectively) between the mounting portion 45a of the guide panel 45 and the optical sheets 43 for restriction in the X, Y-directions as shown in FIG. 2. Furthermore, a minimum of 0.05 mm is overlapped between the mounting portion 45b of the incident light portion guide panel 45 and the optical sheets 43 for restriction in the Z-direction as shown in FIG. 3. Accordingly, a bezel width (a) of at least 5.0 mm is required, and thus restrictive in applying a narrow bezel structure less than 1.5 mm. In this case, an amount of bite between the guide panel 45 and the optical sheets 43 is a maximum of 0.1 mm, and thus restriction in the X, Y-directions is not allowed.
Furthermore, in case of an irregular shape display with a narrow bezel structure, a bezel of the guide panel 45 is narrow, and restrictive in fixing the internal components of the backlight unit. For an example, when the bezel of the guide panel 45 is too narrow to fix the optical sheets 43, due to the detachment and floating of the optical sheets 43 during transfer, rattle noise can occur to generate splitting and light leakage.
In addition, as displays are widely used in various fields while increasing the usage thereof in recent years, the development of displays according to their application fields is required. For an example, a case where one or more holes for allowing mechanical parts in watches such as a second hand, a minute hand, an hour hand or the like to pass therethrough are provided within a screen area of a display should be taken into consideration.